Project Summary The overarching goal of this Mentored Patient-Oriented Research Career Development Award (K23) is to provide Dr. Dawn Sugarman with the training and research activities needed to become an independent investigator with expertise in using digital technology to increase access to evidence-based treatment for women with opioid use disorder (OUD). This application outlines an integrated training and research plan that will provide Dr. Sugarman with the skills needed to achieve her career goal. Under the mentorship of experts in substance use disorders, OUD, and digital health, Dr. Sugarman?s training will focus on the following key areas: (1) digital health design and research (Drs. Lisa Marsch and Kathleen Carroll); (2) etiology and treatment of individuals with OUD (Drs. Shelly Greenfield and Roger Weiss); and (3) statistical methods for longitudinal data analysis (Dr. Garrett Fitzmaurice). Training in these three areas will be achieved through didactic and applied activities, participation in national conferences and institutes, and mentoring meetings. Dr. Sugarman will apply the skills acquired during the training activities to a research project focused on developing an innovative strategy for increasing initiation in medication treatment for opioid use disorder (MOUD) in women with OUD. Research shows that MOUD is effective but underutilized. With rising rates of fatal opioid overdoses in women, it is critical to develop sustainable strategies to engage and retain women in MOUD. Women with OUD have more medical problems, greater functional impairment, and greater psychiatric severity than men with OUD. Gender-specific treatments have been developed for women with substance use disorders and are associated with reduced substance use and increased continuity of care; however, widespread use has been restricted due to in-person delivery models, and they have not been specifically adapted to target engagement in OUD treatment. Moreover, there is a lack of research demonstrating effective strategies to implement this care for women in mixed-gender settings. To address this gap, the proposed K23 research project will utilize a user-centered design process to develop a digital platform to deliver gender- specific care that addresses the individualized needs of women with OUD in mixed-gender settings. The central hypothesis is that a gender-specific digital intervention will overcome the barriers of in-person delivery and will increase women?s initiation in MOUD. This research will address key gaps in treatment for women with OUD by: (1) developing a gender-specific digital intervention (GSDI) for women with OUD; and (2) conducting a pilot randomized controlled trial to examine the feasibility of delivering the GSDI to women with OUD during and immediately after OUD stabilization. Preliminary estimates on the effect of the GSDI on MOUD initiation will also be examined. These data will inform the design of a larger Stage II efficacy trial for a future R01 application. Dr. Sugarman?s training and proposed research will be carried out at McLean Hospital and Harvard Medical School, which will provide her with a multitude of resources to meet her goals.